vmkfstools Performance and Size of disk cloned problem

[blackmscloud]

Goodmorning,

During some test in staging environment we see that to clone a vmdk disk of 100GB, the operation take about 1,40 H. Also, the source disk is configured in Thin mode, so the real size of the data inside is approximately 30 GB. I've seen, anyway, that he copy the entire disk even the byte with 0, so I have to transfer not only the real data size but the all disk.

Is there a way to optimize this process and copy only the data part of the disk?

Thanks in advance for your time.

Alessio

[a_p_]

Welcome to the Community,

which version/build of ESX/ESXi do you currently use? There was an issue in ESX/ESXi 4.0 hwich was resolved with http://kb.vmware.com/kb/1023768

Cloning or migrating a virtual machine with thin as the destination file  format is significantly slower than cloning virtual machines with the  destination file as thick. This issue occurs due to the large number of  operations involved in the cloning of a thin virtual disk.
Installing  this patch reduces the operations involved in cloning targets with thin  file formats and results in a faster thin to thin disk cloning.

André

[blackmscloud]

I'm using ESXi 5.0, I think that it's not affected by this issue.

Any Idea?